新型雙光子吸收分子的合成、性質與應用

Synthesis, Properties, and Applications of New Two-Photon Absorption Molecules

程健彰(Jian-Zhang Cheng)

指導教授 ： 汪根欉

國立臺灣大學/理學院/化學研究所/博士(2013年)

https://doi.org/10.6342/NTU.2013.00027

摘要

本論文主要分成三部分，第一部份：以芴基為核心之 共軛系統，利用鈀金屬催化方式於其2和7位置上，分別引入具有予體(donor)效果的芳香胺和具有受體(acceptor)性質的拉電子基團，如Fl-DCB( = 1620 GM by z-scan)和Fl-BTD( = 623 GM by z-scan)。並更進一步將芴基9號位置修飾上帶三甲基溴化銨的基團，成功的合成出水溶性分子Fl-DCB-TMA4和Fl-BTD-TMA4且以流式細胞儀分析其Fl-BTD-TMA4的生物相容性，證實在經過四小時的細胞培育大多進入HeLa細胞中且不會造成細胞死亡，並以電子顯微鏡觀察其微結構在不同環境下的變化。最後我們也將其衍生物azide-BTA在水溶液中會形成奈米球粒子的特性，運用在電致化學放光上並獲得其電致化學放光光譜。
第二部分：由實驗室之前的研究指出芴酮分子DAF具有良好的單重態氧的生成效率(>100%以H2TPP為參考品)，因此我們在其上引入乙二醇支鏈形成親水性的EDAF和引入三甲基溴化銨支鏈形成水溶性的DAF-TMA2跟DAF-TMA4，其中DAF-TMA4對水的最大溶解度(40 mg/mL)與DAF(3 g/mL)相比提升了13000倍。並且同樣以流式細胞儀分析其DAF-TMA2的生物相容性，證實在經過半小時的細胞培育大多進入HeLa細胞中且不會造成細胞死亡。另外也合成具雙酮基的菲醌衍生物DAPQ和EDAPQ來與芴酮衍生物相比，發現其單氧量子產率以DAF-TMA4為最好(>100%以Rose Bengal為參考品)，其他分子則落在50-10%之間。在雙光子吸收的部分，我們所新設計的分子其值都小於100 GM。
第三部分：以方酸為主體核心在含氮雜環上引入不同支鏈或延伸其主共軛鏈，可得到InSQ、InSQ-TMA2、InSQ-DEA2和PySQ，雙光子吸收截面分別為202±20、186±19、155±16和5060±500 GM (by TPEF)。其中InSQ-DEA2在pH值低於9.4時會被質子化，導致水溶性大幅提升，此種特性可以運用在辨識高酸性環境的癌細胞上。另外我們也用勞森試劑合成出一系列以硫取代的方酸衍生物，並發現硫取代的方酸衍生物S2-InSQ其單氧量子產率更能提升至50%，非常適合應用在光動力療法上。

關鍵字

雙光子吸收 ； 光動力療法 ； 雙光子螢光顯微術

並列摘要

Two-photon absorption (TPA) process is a nonlinear absorption process involving the simultaneous absorption of two photons. Recently, TPA chromophore has attracted considerable attention in many research fields owing to its wide practical applications such as three-dimensional optical data storage, microfabrication, two-photon fluorescence microscopy, optical limiting and photodynamic therapy. Chromophoreswith high capability of TPA are desired for all these applications because a greater degree of excitation can be achieved with lower laser intensity. Thus, in order to shed light onto the design of molecules for increasing the TPA cross section and for tuning the position of the two-photon absorption peak wavelength, there is an urgent need to unveil the structure-propertyrelationship for two-photon absorbing molecules.

This thesis is composed of three major parts. For the first part, we have successfully synthesized a series of new quadrupolar molecules with various donors and acceptors which were bridged with a fluorene conjugation. The donors, mainly diaryl amino group was introduced onto the C2 of fluorene core employing palladium-catalyzed C-N bond coupling reaction. The resulting donor-equipped intermediate was connected to the acceptors such as dicyanobenzene and benzothiadiazole by employing Suzuki coupling reaction to afford new TPA chromophores Fl-DCB (=1620 GM by z-scan) and Fl-BTD (= 623 GM by z-scan), respectively. We also successfully synthesized water-soluble TPA molecules Fl-DCB-TMA4 and Fl-BTD-TMA4 by introducing trimethylaminium bromide group onto the long alkyl chains at C9 of fluorene core. The water-soluble molecue (Fl-BTD-TMA4) was found to have biocompatibility by flow cytometry analysis and confirmed the dye molecules can enter HeLa cells after 4 hours observed by fluorescence microscope. The amphiphlic behavior of ionic group end-capping water-soluble has interesting propensity of self-assembling into interesting nano structures under different solvents. In addition, we utilized the structural blocks to synthesize a TPA derivative azide-BTA which can apply to give nanoparticles in water solution and performed electrogenerated chemiluminescence (ECL).
Our previous studying pointed out that the new donor-acceptor molecule (DAF) has great singlet oxygen generation quantam yield (> 100% as compared to that of standard H2TPP). In the second part of this thesis, we introduced oligoethylene glycol side chains and trimethylammonium bromide end-capped side chains on the diarylamine of DAF to for increasing the water solubility to give new DAF-based molecules EDAF, DAF-TMA2, and DAF-TMA4. Among them, we found the water-solubility of DAF-TMA4 (40 mg/mL) was increased by thirteen thousand times as compared to that of parent DAF (3 g/mL). We then used flow cytometry to study the biocompatibility of DAF-TMA2 and utilized fluorescence microscope to confirm the dyes can enter HeLa cells after half an hour. We also synthesized phenanthraquinone-based derivatives DAPQ and EDAPQ to compare with fluorenone-based derivatives. We found the singlet oxygen generation quantum yield of DAF-TMA4is better than those of other fluorenone-based or phenanthraquinone-based derivatives. All of our new fluorenone-based or phenanthraquinone-based derivatives were found to give small TPA cross-section (<100 GM).
For the third part, we focused on the squaraine-basd TPA molecules. We introduced different side chains or extended the conjugation to give new TPA molecules InSQ, InSQ-TMA2, InSQ-DEA2, and PySQ. Among them, we found PySQ gave the highest TPA cross section up to 5060±500 GM (by TPEF). We found that InSQ-DEA2 can be protonated as the pH value of solution lower than 9.4, which led to enhanced water-solubility. In addition, we also synthesized a series of sulfur-containing squaraine TPA molecules S2-InSQ, S1-PySQ, and S2-PySQ in order to increase singlet oxygen generation quantum yield and TPA cross-section. For S2-InSQ, the singlet oxygen generation quantam yield was found to be 50%.

並列關鍵字

Two-Photon Absorption ； Photodynamic Therapy ； Two-Photon Fluorescence Microscopy

參考文獻

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